Voice coil motor

ABSTRACT

A VCM is disclosed, the VCM including a rotor including a bobbin arranged at an upper surface of a base formed with an opening, and a driving coil wound on the bobbin, a stator including a driving magnet opposite to the driving coil, and a yoke secured by the driving magnet at an inner surface of a lateral plate, and a tilting unit including a tilt magnet arranged at an outer surface of the lateral plate, a housing fixing the tilt magnet, and a tilt coil unit opposite to the tilt magnet.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.16/687,186, filed Nov. 18, 2019; which is a continuation of U.S.application Ser. No. 15/065,190, filed Mar. 9, 2016, now U.S. Pat. No.10,516,326, issued Dec. 24, 2019; which is a continuation of U.S.application Ser. No. 13/676,628, filed Nov. 14, 2012, now U.S. Pat. No.9,300,196, issued Mar. 29, 2016; which claims the benefit under 35U.S.C. § 119 of Korean Patent Application Nos. 10-2011-0119351, filedNov. 16, 2011; 10-2011-0141199, filed Dec. 23, 2011; 10-2011-0141200,filed Dec. 23, 2011; and 10-2011-0141201, filed Dec. 23, 2011, which arehereby incorporated by reference in their entirety.

BACKGROUND Field of the Invention

The present disclosure relates to a VCM (Voice Coil Motor).

Description of Related Art

Recently, a mobile phone mounted with a camera module storing an objectas a digital image or a video, a smart phone and a smart pad of a typeof a portable personal computer.

A conventional camera module includes a lens and an image sensor moduleconverting light having passed the lens to a digital image. However, theconventional camera module suffers from disadvantages of disablement ofauto focus function to adjust a gap between a lens and an image sensor,and lack of function to correct a handshake in handshake-stricken mobilephones, smart phones and smart pads.

Accordingly, there is room for improvement in the camera module.

BRIEF SUMMARY

The present invention is directed to provide a compact VCM (Voice CoilMotor) configured to include an auto focus function and a handshakecorrection function, to obtain a space for realizing the handshakecorrection function, to reduce a volume, a height and an area, and toenhance a tilting performance of a rotor.

Technical problems to be solved by the present disclosure are notrestricted to the above-mentioned descriptions, and any other technicalproblems not mentioned so far will be clearly appreciated from thefollowing description by skilled in the art.

An object of the invention is to solve at least one or more of the aboveproblems and/or disadvantages in whole or in part and to provide atleast the advantages described hereinafter. In order to achieve at leastthe above objects, in whole or in part, and in accordance with thepurposes of the invention, as embodied and broadly described, and in onegeneral aspect of the present invention, there is provided a VCM, theVCM comprising: a rotor including a bobbin arranged at an upper surfaceof a base formed with an opening, and a driving coil wound on thebobbin; a stator including a driving magnet opposite to the drivingcoil, and a yoke secured by the driving magnet at an inner surface of alateral plate; and a tilting unit including a tilt magnet arranged at anouter surface of the lateral plate, a housing fixing the tilt magnet,and a tilt coil unit opposite to the tilt magnet.

The VCM according to the present disclosure has an advantageous effectin that a signal line of a flexible circuit board for tiling an imagesensor along with a rotor is dispersively arranged to inhibit an area ofthe flexible circuit board from being increased, and the flexiblecircuit board is inserted into the image sensor arranged on an uppersurface of the rigid circuit board to inhibit the VCM from beingincreased in terms of volume and height.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings, the width, length, thickness, etc. of components may beexaggerated or reduced for the sake of convenience and clarity.Furthermore, throughout the descriptions, the same reference numeralswill be assigned to the same elements in the explanations of thefigures, and explanations that duplicate one another will be omitted.Now, a voice coil motor according to the present disclosure will bedescribed in detail with reference to the accompanying drawings.

The teachings of the present disclosure can be readily understood byconsidering the following detailed description in conjunction with theaccompanying drawings, in which:

FIG. 1 is an exploded perspective view illustrating a VCM according to afirst exemplary embodiment of the present disclosure;

FIG. 2 is an assembled cross-sectional view of FIG. 1 ;

FIG. 3 is an extracted perspective view illustrating a housing and atilt magnet of FIG. 1 ;

FIG. 4 is an exploded perspective view illustrating a VCM according to asecond exemplary embodiment of the present disclosure;

FIG. 5 is an assembled cross-sectional view of FIG. 4 ;

FIG. 6 is an extracted perspective view illustrating a housing and atilt magnet of FIG. 4 ;

FIG. 7 is an extracted perspective view illustrating a tilt coil drivingunit of FIG. 4 ;

FIG. 8 is an exploded perspective view illustrating a VCM according to athird exemplary embodiment of the present disclosure;

FIG. 9 is an assembled cross-sectional view of FIG. 8 ;

FIG. 10 is an extracted perspective view illustrating a housing and atilt magnet of FIG. 8 ;

FIG. 11 is a perspective view illustrating a flexible circuit boardmounted with a rigid circuit board of FIG. 8 ;

FIG. 12 is a perspective view illustrating a state of a second boardunit of a flexible circuit board that is not bent;

FIG. 13 is a perspective view illustrating a state of a second boardunit of a flexible circuit board of FIG. 12 that is bent;

FIG. 14 is an exploded perspective view illustrating a VCM according toa fourth exemplary embodiment of the present disclosure;

FIG. 15 is an assembled cross-sectional view of FIG. 14 ;

FIG. 16 is an extracted perspective view illustrating a housing and atilt magnet of FIG. 14 ;

FIG. 17 is a perspective view illustrating a flexible circuit board ofFIG. 15 ; and

FIG. 18 is a cross-sectional view taken along line I-I′ of FIG. 17 .

DETAILED DESCRIPTION

Advantages and features of the present disclosure may be understood morereadily by reference to the following detailed description of exemplaryembodiments and the accompanying drawings. Detailed descriptions ofwell-known functions, configurations or constructions are omitted forbrevity and clarity so as not to obscure the description of the presentdisclosure with unnecessary detail. Thus, the present disclosure is notlimited to the exemplary embodiments which will be described below, butmay be implemented in other forms.

The meaning of specific terms or words used in the specification andclaims should not be limited to the literal or commonly employed sense,but should be construed or may be different in accordance with theintention of a user or an operator and customary usages. Therefore, thedefinition of the specific terms or words should be based on thecontents across the specification.

Now, exemplary embodiments of a VCM (Voice Coil Motor) according to thepresent disclosure will be explained in detail together with thefigures.

First Exemplary Embodiment

FIG. 1 is an exploded perspective view illustrating a VCM according to afirst exemplary embodiment of the present disclosure, FIG. 2 is anassembled cross-sectional view of FIG. 1 , and FIG. 3 is an extractedperspective view illustrating a housing and a tilt magnet of FIG. 1 .

Referring to FIGS. 1, 2 and 3 , a voice coil motor (hereinafter referredto as VCM, 700) may include a rotor (100), a stator (200), a tilt unit(300) and a cover can (400). In addition, the VCM (700) may furtherinclude an elastic member (500) and a base unit (600).

The rotor (100) is mounted with a lens (105), and serves to perform anauto focusing function by vertically moving relative to an upper surface(horizontal plane) of the base unit (600) arranged at a rear side withan image sensor. Furthermore, the rotor (100) performs a handshakecorrection function by tiling to four (4) directions relative to theupper surface (horizontal plane) of the base unit (600) in response tothe tilt unit (300). The rotor (100) includes a bobbin (110) and adriving coil (120). In addition, the rotor (100) may further include alens barrel (130) and a lens (105).

The bobbin (110) takes a cylindrical shape opened at an upper surfaceand a bottom surface, and is formed at an inner surface with a femalescrew thread for securing the lens barrel (130). The lens barrel (130)is coupled by the lens (105). FIG. 2 illustrates the lens barrel (130)not coupled to the lens (105).

The driving coil (120) is formed by winding an insulated long wire in acylindrical shape, and is arranged at an outer surface of the bobbin(110). The driving coil (120) may be directly wound on the outer surfaceof the bobbin (110), or may be attached to the outer surface of thebobbin (110) using an adhesive.

Referring to FIG. 1 , the bobbin (110) is overlappingly arranged at abottom surface with first and second driving elastic members (510, 515),both of which comprise an elastic member (500). The first drivingelastic member (510) is coupled to the bottom surface of the bobbin(110) in an insulated state, and is electrically connected to eachdistal end of the driving coil (120). Each of the first driving elasticmembers (510) is electrically connected to a driving circuit board (626,described later), and a driving signal outputted from the drivingcircuit board (626) passes the first and second driving elastic members(510, 515) to be applied to the driving coil (120).

The first and second driving elastic members (510, 515) are respectivelyfixed to a square-shaped base (610) which is one of constituent elementsof the base unit (600), and to a case (630, described later). The seconddriving elastic members (515) is elastically coupled to a bottom surfaceof a housing (320, described later) to provide elasticity to the housingto return to an original position after the housing (320) is tilted.

The base (610) is fixed at a bottom surface thereof by a holder (620)having an opening (622) opposite to the lens (105) coupled to the bobbin(110), where the holder (620) is arranged at an inner surface with an IR(Infrared) filter (624) covering the opening (622) as shown in FIG. 2 .The holder (620) is arranged at an inner surface with an image sensor(625) opposite to the IR filter (624), where the image sensor (625) ismounted at the driving circuit board (626).

The base (610) and the holder (620) are accommodated inside asquare-framed case (630), and the driving circuit board (626) ispress-fitted into and fixed at a lug (632) protruded from a bottomsurface of the case (630). The case (630) is coupled to a bottom covercan (420) by way of a hook coupling method.

The stator (200) includes a yoke (210) and a driving magnet (220). Theyoke (210) is arranged opposite to the driving coil (120) of the rotor(100), and includes an upper plate (212) and a lateral plate (214). Theupper plate (212) of the yoke (210) takes a shape of a square plateformed with an opening through which light having passed the lens (105)passes, and the lateral plate (214), four (4) in total, is extended froman edge of the upper plate (212).

The driving magnet (220), four (4) in total, for example, is fixed to aninner surface of the lateral plate (214), and arranged opposite to thedriving coil (120). The rotor (100) is moved to a direction facing anupper surface of the base (610) by forces generated by a magnetic fieldfrom the driving magnet (220) and a magnetic field from the driving coil(120). A gap between the image sensor (625) arranged at a rear surfaceof the base (610) and the lens (105) can be adjusted by the rotor (100)moving to the direction facing an upper surface of the base (610).

The tilt unit (300) includes a tilt magnet (310), a housing (320), atilt coil unit (330) and a spacer (340). The tilt magnet (310) isarranged at an outer surface of the lateral plate (214) of the yoke(210). Each of the tilt magnets (310), four (4) in total, is arranged oneach of the four (4) lateral plates (214) of the yoke (210). In theexemplary embodiment of the present disclosure, each of the tilt magnets(310) may include a 2-pole magnetizing flat magnet, or a 4-polemagnetizing flat magnet, for example. The tilt magnets (310) is fixed tothe lateral plate (214) of the yoke (210) using the housing (320). Thehousing (320) takes a shape of an upper surface and a bottomsurface-opened cylinder, and is coupled to an outer surface of thelateral plates (214) of the yoke (210).

Each of four lateral plates (321) at the housing (320) is formed with anopening (322) for fixing each of the tilt magnets (310), and the tiltmagnet (310) is arranged on the yoke (210) using each of the opening(322). The tilt coil unit (330) includes a tilt coil (332), a tile coilhousing (334) and a tilt coil driving unit (336).

The tilt coil (332) is formed by winding an insulated coil in arectangular shape centrally formed with a slip-type opening, and isarranged opposite to the four (4) tilt magnets (310) each coupled toeach of the four (4) lateral plates (321) of the housing (320). In theexemplary embodiment of the present disclosure, a gap (G) is formedbetween a surface of the tilt coil (332) and the tilt magnet (310) forhorizontal tilting of the rotor (100).

The tile coil housing (334) functions to fix each of the tilt coils(332) arranged opposite to the four (4) tilt magnets (310). The tilecoil housing (334) is opened at an upper surface and a bottom surface,and includes four (4) lateral surfaces (335), and is formed at eachlateral surface (335) thereof with an opening for fixing each of thetilt coils (332).

The tilt coil driving unit (336) functions to apply a tilt drivingsignal to each of the tilt coils (332), may include a flexible circuitboard, and is electrically connected to each of the tilt coils (332)while covering each of the tilt coils (332).

Meanwhile, a part of the elastic member (520) is arranged on an uppersurface of the housing (320) fixing the tilt magnet (310) and on anupper surface (212) of the yoke (210), and a part of the elastic member(520) is fixed by the bobbin (110). That is, the bobbin (110) iselastically coupled by a pair of elastic members (510) coupled to thebottom surface of the bobbin (110) and the elastic member (520) coupledto the upper surface of the bobbin (110).

The cover can (400) inhibits the rotor (100), the stator (200), the tiltunit (300) and the elastic member (500) from being destructed by outsidevibration and shock. The cover can (400) includes an upper cover can(410) and a bottom cover can (420). The upper cover can (410) includesan upper plate (412) and a lateral plate (414). The upper plate (412) ofthe cover can (400) takes a shape of a square plate having an openingexposing the lens (105), and the lateral plate (414) is extended fromthe upper plate (412).

In the exemplary embodiment of the present disclosure, the rotor (100)is horizontally tilted by a magnetic field generated from the tiltmagnet (310) and a magnetic field from the tilt coil (332) to perform ahandshake correction function, and the rotor (100) is vertically movedby the magnetic field from the driving magnet (220) and the magneticfield from the driving coil (120) to perform an auto focusing function.

In order for the rotor (100) to perform the handshake correctionfunction by horizontal tilt and to perform the auto focusing function byvertical movement, a space must be formed between an inner surface ofthe upper plate (412) of the upper cover can (410) and the rotor (100).However, in a case a large space is formed between an inner surface ofthe upper plate (412) of the upper cover can (410) and the rotor (100)to perform the handshake correction function or the auto focusingfunction, it is inevitable that an entire volume and a height of the VCM(700) are greatly increased.

In order to perform the handshake correction function or the autofocusing function without increasing the entire volume and the height ofthe VCM (700) in the exemplary embodiment of the present disclosure, anupper surface (323) of the housing (320) opposite to the inner surfaceof the upper plate (412) of the upper cover can (410) of the cover can(400) is placed at a position lower than an upper end of the bobbin(110) of the rotor (100). The upper surface (323) of the housing (320)is arranged at a position lower than the upper end of the bobbin (110).Preferably, the upper surface (323) of the housing (320) may be arrangedon a same planar surface as that of the upper surface (212) of the yoke(210).

In a case the upper surface (323) of the housing (320) is placed at aposition lower than the upper end of the bobbin (110), or on a sameplanar surface as that of the upper surface (212) of the yoke (210), theupper surface (323) of the housing (320) coupled to the rotor (100)performing a handshake correction function by being horizontally tiltedrelative to the horizontal surface or to the rotor (100) verticallymoving relative to the horizontal surface is formed with a space notinterfered with an inner surface of the upper plate (412) of the uppercover can (410) or the tilt coil driving unit (336).

Furthermore, in a case the upper surface (323) of the housing (320) isplaced at a position lower than the upper end of the bobbin (110), or ona same planar surface as that of the upper surface (212) of the yoke(210), the entire volume and the height of the VCM (700) are notincreased.

In order to inhibit the upper cover can (410) of the housing (320) frombeing interfered with the upper surface (212) of the housing (210), athickness of the lateral plate (321) of the housing (210) is formed lessthan the thickness of the tilt magnet (310), whereby a part of the uppersurface (212) of the housing (210) is exposed from the tilt magnet(310).

Meanwhile, the upper surface (323) of the housing (320) is arranged withthe elastic member (520) and the elastic member (520) is fixed by thespacer (340), and in order for the spacer (340) to inhibit the rotor(100) from being interfered with the cover can (410) of the cover can(400) or with the tilt coil driving unit (336), an upper surface (341)of the spacer (340) is arranged at a position lower than the upper endof the bobbin (110), and a lateral surface of the spacer (340) ispreferably so formed as not to protrude from an outer surface of thelateral plate (321).

As mentioned in detail in the above description, the VCM according tothe present disclosure has an advantageous effect in that a tilt spacefor performing an auto focusing function adjusting a gap between a lenspassed by an outside light and an image sensor generating an imagecorresponding to the outside light having passed the lens and forperforming a handshake correction function without increased volume andthickness of the VCM can be sufficiently provided, whereby generation ofan interference among constituent elements due to lack of tilt space canbe inhibited during the handshake correction operation and auto focusingoperation.

Second Exemplary Embodiment

FIG. 4 is an exploded perspective view illustrating a VCM according to asecond exemplary embodiment of the present disclosure, FIG. 5 is anassembled cross-sectional view of FIG. 4 , FIG. 6 is an extractedperspective view illustrating a housing and a tilt magnet of FIG. 4 ,and FIG. 7 is an extracted perspective view illustrating a tilt coildriving unit of FIG. 4 .

Referring to FIGS. 4 to 7 , a voice coil motor (hereinafter referred toas VCM, 700) may include a rotor (100), a stator (200), a tilt unit(300), a rigid circuit board (700) and a flexible circuit board (800).In addition, the VCM (700) may further include a cover can (400),elastic members (500) and a base unit (600).

The rotor (100) is mounted with a lens (105), and serves to perform anauto focusing function by vertically moving relative to an upper surfaceof the base unit (600) arranged at a rear side with an image sensor.Furthermore, the rotor (100) performs a handshake correction function byhorizontally tiling relative to the upper surface (or horizontal plane)of the base unit (600) in response to the tilt unit (300, describedlater). The rotor (100) includes a bobbin (110) and a driving coil(120). In addition, the rotor (100) may further include a lens barrel(130) and a lens (105).

The bobbin (110) takes a cylindrical shape opened at an upper surfaceand a bottom surface. The lens barrel (130) is coupled by the lens(105). FIG. 5 illustrates the lens barrel (130) not coupled to the lens(105). The bobbin (110) may be formed by injection molding process inthe exemplary embodiment of the present disclosure.

The driving coil (120) is formed by winding an insulated long wire in acylindrical shape, and is arranged at an outer surface of the bobbin(110). The driving coil (120) may be directly wound on the outer surfaceof the bobbin (110), or may be attached to the outer surface of thebobbin (110) using an adhesive.

Referring to FIG. 4 , the bobbin (110) is arranged at a bottom surfacewith a first elastic member (520) which is one of the elastic member(500), and the first elastic member (520) is overlappingly arranged withfirst and second driving elastic members (510, 515).

The first and second driving elastic members (510, 515) are respectivelyfixed to a square-shaped base (610) which is one of constituent elementsof the base unit (600, described later), and to a bottom spacer (630,described later). The second driving elastic members (515) iselastically coupled to a bottom surface of a housing (320, describedlater) to provide elasticity to the housing to return to an originalposition after the housing (320) is tilted.

The second driving elastic member (515) is electrically connected to atilt coil driving unit (336) of a tilt coil unit (330, described later).A driving signal applied to the tilt coil driving unit (336) is appliedto the driving coil (120) through the second driving elastic member(515) and the first driving elastic member (510).

The base (610) is fixed at a bottom surface thereof by a holder (620)having an opening (622) opposite to the lens (105) coupled to the bobbin(110), where the holder (620) is arranged at an inner surface with an IR(Infrared) filter (624) covering the opening (622) as shown in FIG. 5 .The holder (620) is arranged at an inner surface with an image sensor(625) opposite to the IR filter (624), where the image sensor (625) ismounted at a rigid circuit board (700) and electrically connected to therigid circuit board (700).

A technical term of ‘rigid circuit board (700)’ to be frequently used inthe present disclosure may be defined as a circuit board that is notflexible and difficult to be bent. The rigid circuit board (700) isshaped of a flat plate formed with a thin thickness, and is formed witha size adequate enough to be fixed into an inner surface of the holder(620).

The rigid circuit board (700) coupled to the holder (620) is tiltedalong with the base (610) and the holder (620), because the holder (620)is coupled to the base (610), whereby the image sensor (625)electrically connected to the rigid circuit board (700) is also tiltedalong with the rigid circuit board (700).

A flexible circuit board (800) is brought into contact with a bottomsurface of the rigid circuit board (700) and is electrically connectedto the rigid circuit board (700) to thereby provide an adequatestructure, where a driving signal is provided to the rigid circuit board(700) and the rigid circuit board (700) is tilted along with the holder(620).

The flexible circuit board (800) includes a first board unit (810), asecond board unit (820) and a third board unit (830). The first, secondand third board units (810, 820, 830) may be integrally formed in theexemplary embodiment of the present disclosure.

The flexible first board unit (810) is formed with a shape and sizesimilar to those of the rigid circuit board (700), and supports therigid circuit board (700). In a non-limiting example, an upper surfaceof the first board unit (810) and the rigid circuit board (700) may beattached together using an adhesive.

Meanwhile, a bottom surface of the holder (620) is formed at an edge ofthe first board unit (810), and the second board unit (820) provides atilt structure for the first board unit (810) to tilt relative to thesecond board unit (820). The second board unit (820) is symmetricallyformed in a pair relative to the first board unit (810) to allow thefirst board unit (810) to tilt. The pair of second board units (820)takes a shape of a band, and each distal end of both sides of the secondboard units (820) is connected to both edges facing the first board unit(810). Each of the pair of second board units (820) wraps three (3)edges adjacent to the first board unit (810), and each of the secondboard units (820) is symmetrically formed relative to a center of thefirst board unit (810).

Each of the second board units (820) symmetrically formed relative tothe first board unit (810) is formed with a through hole, where each ofthe through holes is fixed by lugs protruded from the bottom spacer(630). The first board unit (810) is tilted from the second board unit(820) due to fixture of the second board units (820) to the bottomspacer (630).

Each of the pair of second board units (820) is formed with a signalline electrically connected to the rigid circuit board (700), where thesignal lines formed on the second board units (820) are extended to thethird board units (830, described later) and the signal lines areelectrically connected to an outside circuit board through the thirdboard units (830). The third circuit board unit (830) is integrallyformed with any one of the second board units (820).

The base (610) and the holder (620) are accommodated inside asquare-framed bottom spacer (630), and the through hole of the secondboard unit (820) of the flexible circuit board (800) is press-fitted bya lug protruded from a bottom end of the bottom spacer (630). The bottomspacer (630) is coupled to a bottom cover can (420) by way of a hookcoupling method.

The stator (200) includes a yoke (210) and a driving magnet (220). Theyoke (210) is arranged opposite to the driving coil (120) of the rotor(100), and includes an upper plate (212) and a lateral plate (214). Theupper plate (212) of the yoke (210) takes a shape of a square plateformed with an opening through which light having passed the lens (105)passes, and the lateral plate (214), four (4) in total, is extendeddownwards from an edge of the upper plate (212).

The driving magnet (220), four (4) in total, for example, is fixed to aninner surface of the lateral plate (214), and arranged opposite to thedriving coil (120).

The rotor (100) is moved to a direction facing an upper surface of thebase (610) by forces generated by a magnetic field from the drivingmagnet (220) and a magnetic field from the driving coil (120). A gapbetween the image sensor (625) arranged at a rear surface of the base(610) and the lens (105) can be adjusted by the rotor (100) moving tothe direction facing an upper surface of the base (610).

The tilt unit (300) includes a tilt magnet (310), a housing (320), atilt coil unit (330) and a spacer (340). The tilt magnet (310) isarranged at an outer surface of the lateral plate (214) of the yoke(210). Each of the tilt magnets (310), four (4) in total, is arranged oneach of the four (4) lateral plates (214) of the yoke (210). In theexemplary embodiment of the present disclosure, each of the tilt magnets(310) may include a 2-pole magnetizing flat magnet, or a 4-polemagnetizing flat magnet, for example.

Although the tilt magnets (310) may be directly arranged on the lateralplate (214) of the yoke (210), the tilt magnet (310) is fixed to thelateral plate (214) of the yoke (210) using the housing (320) in theexemplary embodiment of the present disclosure.

Referring to FIG. 6 , the housing (320) takes a shape of an uppersurface-opened and a bottom surface-opened cylinder, and is coupled toan outer surface of the lateral plates (214) of the yoke (210).

Each of four lateral plates (321) at the housing (320) is formed with anopening (322) for fixing each of the tilt magnets (310), and the tiltmagnet (310) is arranged on an outer surface of the yoke (210) usingeach of the opening (322).

Referring to FIG. 4 , the tilt coil unit (330) includes a tilt coil(332), a tilt coil housing (334) and a tilt coil driving unit (336).

The tilt coil (332) is formed by winding an insulated coil in arectangular shape to allow a slit-shaped opening to be centrally formed,and is arranged opposite to the four (4) tilt magnets (310) each coupledto each of four (4) lateral plates (321) of the housing (320). Becausethe tilt coil (332) must be arranged opposite to the four (4) tiltmagnets (310), four (4) tilt coils (332) must be formed in the samenumber as that of the tilt magnets (310). A gap is formed between asurface of the tilt coil (332) and the tilt magnet (310) to allow therotor (100) to horizontally tilt. Both distal ends (332 a, 332 b) of theinsulated coil forming the tilt coil (332) are protruded to an uppersurface of the tilt coil (332).

In the exemplary embodiment of the present disclosure, the tilt coil(332) and the tilt magnet (310) are arranged to face each other, and anempty space is formed between the tilt coil (332) and the tilt magnet(310) to further enhance the forces generated by magnetic field from thetilt coil (332) and the magnetic field from the tilt magnet (310).

The tilt coil housing (334) serves to fix each of the tilt coils (332)arranged opposite to the four (4) tilt magnets (310). The tilt coilhousing (334) is opened at an upper surface and a bottom surface, andincludes four (4) lateral surfaces (335), and each of the lateralsurfaces (335) of the tilt coil housing (334) are formed with openingsfor fixing each of the tilt coils (332).

Referring to FIG. 7 , the tilt coil driving unit (336) functions toapply a tilt driving signal to each of the tilt coils (332), may includea flexible circuit board, and covers each of the tilt coils (332) to beelectrically connected to each of the tilt coils (332). The tilt coildriving unit (336) includes a first tilt coil driving unit (337), asecond tilt coil driving unit (338) and a third tilt coil driving unit(339).

The first, second and third tilt coil driving units (337, 338, 339) areintegrally formed in the exemplary embodiment of the present disclosure,and each of the first, second and third tilt coil driving units (337,338, 339) includes a flexible circuit board.

The first tilt coil driving unit (337) is arranged at an upper surfaceof the tilt coil housing (334), and takes a shape of a square bandformed therein with an opening. The second tilt coil driving unit (338)is extended from an outer surface of the first tilt coil driving unit(337) formed in the shape of a square band. Each of the second tilt coildriving units (338) takes a shape of a square plate covering a rearsurface of the four (4) tilt coils (332).

In the exemplary embodiment of the present disclosure, the second tiltcoil driving units (338) are coupled to a rear surface of the tilt coil(332) opposite to the tilt magnets (310). The second tilt coil drivingunits (338) and the tilt coil (332) may be mutually attached by using anadhesive, for example.

Because the second tilt coil driving units (338) are coupled to a rearsurface of the tilt coil (332) using an adhesive in the exemplaryembodiment of the present disclosure, an empty space is formed betweenthe tilt coil (332) and the tilt magnets (310), whereby a tiltperformance of the rotor (100) can be further enhanced by the magneticfield generated by the tilt coil (332) and the tilt magnet (310).

A part of the second tilt coil driving units (338) is electricallyconnected to a part of the driving coil (120) electrically connected tothe first elastic member (520).

Meanwhile, connection openings (337 a) are formed between the first andsecond tilt coil driving units (337, 338), where the connection openings(337 a) are formed at a position corresponding to that of the bothdistal ends (332 a, 332 b) of the tilt coil (332). The both distal ends(332 a, 332 b) of the tilt coil (332) are inserted into the connectionopenings (337 a), and may be electrically connected to a terminal formedat the first tilt coil driving unit (337) using a welding or aconductive adhesive tape. Furthermore, the terminal formed at the firsttilt coil driving unit (337) and the both distal ends (332 a, 332 b) ofthe tilt coil (332) can be easily assembled by electrical connectionfrom outside.

The third tilt coil driving unit (339) is extended from any one of thefour (4) second tilt coil driving units (338), electrically connected toan outside circuit board, and a tilt driving signal applied from theoutside circuit board is applied to the tilt coil (332) through thethird tilt coil driving unit (339), the second tilt coil driving unit(338) and the first tilt coil driving unit (337).

The third tilt coil driving unit (339) in the exemplary embodiment ofthe present disclosure is formed in parallel with the third board unit(830) of the circuit board (800). Meanwhile, a part of the secondelastic member (530) which is one of the elastic member (500) isarranged on the upper surface of the housing (320) fixing the tiltmagnet (310) and on the upper surface of the yoke (210), and a part ofthe second elastic member (530) is fixed by the bobbin (110). That is,the bobbin (110) is elastically coupled by the first elastic member(520) coupled to the bottom end of the bobbin (110) and the secondelastic member (530) coupled to the upper surface of the bobbin (110).

The cover can (400) inhibits the rotor (100), the stator (200), the tiltunit (300) and the elastic member (500) from being destructed by outsidevibration and shock. The cover can (400) includes an upper cover can(410) and a bottom cover can (420). The upper cover can (410) includesan upper plate (412) and a lateral plate (414). The upper plate (412) ofthe cover can (400) takes a shape of a square plate having an openingexposing the lens (105), and the lateral plate (414) is extended fromthe upper plate (412).

In the exemplary embodiment of the present disclosure, the rotor (100)is horizontally tilted by a magnetic field generated from the tiltmagnet (310) and a magnetic field from the tilt coil (332) to perform ahandshake correction function, and the rotor (100) is vertically movedby the magnetic field from the driving magnet (220) and the magneticfield from the driving coil (120) to perform an auto focusing function.

In order for the rotor (100) to perform the handshake correctionfunction by horizontal tilt and to perform the auto focusing function byvertical movement, a space must be formed between an inner surface ofthe upper plate (412) of the upper cover can (410) and the rotor (100).However, in a case a large space is formed between the inner surface ofthe upper plate (412) of the upper cover can (410) and the rotor (100)to perform the handshake correction function or the auto focusingfunction, it is inevitable that an entire volume and a height of the VCM(900) are greatly increased.

In order to perform the handshake correction function or the autofocusing function without increasing the entire volume and the height ofthe VCM (700) in the exemplary embodiment of the present disclosure, anupper surface (323) of the housing (320) opposite to the inner surfaceof the upper plate (412) of the upper cover can (410) of the cover can(400) is placed at a position lower than an upper end of the bobbin(110) of the rotor (100). The upper surface (323) of the housing (320)is arranged at a position lower than the upper end of the bobbin (110).Preferably, the upper surface (323) of the housing (320) may be arrangedon a same planar surface as that of the upper surface (212) of the yoke(210).

In a case the upper surface (323) of the housing (320) is placed at aposition lower than the upper end of the bobbin (110), or on a sameplanar surface as that of the upper surface (212) of the yoke (210), theupper surface (323) of the housing (320) coupled to the rotor (100)performing a handshake correction function by being horizontally tiltedrelative to the horizontal surface or to the rotor (100) verticallymoving relative to the horizontal surface is formed with a space notinterfered with an inner surface of the upper plate (412) of the uppercover can (410) or the tilt coil driving unit (336).

Furthermore, in a case the upper surface (323) of the housing (320) isplaced at a position lower than the upper end of the bobbin (110), or ona same planar surface as that of the upper surface (212) of the yoke(210), the entire volume and the height of the VCM (900) are notincreased.

In order to inhibit the upper cover can (410) of the housing (320) frombeing interfered with the upper surface (212) of the housing (210), athickness of the lateral plate (321) of the housing (210) is formed lessthan the thickness of the tilt magnet (310), whereby a part of the uppersurface (212) of the housing (210) is exposed from the tilt magnet(310).

Meanwhile, the upper surface (323) of the housing (320) is arranged withthe second elastic member (530), and the second elastic member (530) isfixed by the spacer (340), and in order for the spacer (340) to inhibitthe rotor (100) from being interfered with the cover can (410) of thecover can (400) or with the tilt coil driving unit (336), an uppersurface (341) of the spacer (340) is arranged at a position lower thanthe upper end of the bobbin (110), and a lateral surface of the spacer(340) is preferably so formed as not to protrude from an outer surfaceof the lateral plate (321) of the housing (210).

As mentioned in detail in the above description, the VCM according tothe present disclosure has an advantageous effect in that a fixingstructure and an electrical structure tilting a rotor are enhanced toimprove an attractive force and a repulsive force acting between a tiltcoil and a tilt magnet, whereby a tilt performance can be furtherimproved.

Third Exemplary Embodiment

FIG. 8 is an exploded perspective view illustrating a VCM according to athird exemplary embodiment of the present disclosure, FIG. 9 is anassembled cross-sectional view of FIG. 8 , FIG. 10 is an extractedperspective view illustrating a housing and a tilt magnet of FIG. 8 ,FIG. 11 is a perspective view illustrating a flexible circuit boardmounted with a rigid circuit board of FIG. 8 , FIG. 12 is a perspectiveview illustrating a state of a second board unit of a flexible circuitboard that is not bent, and FIG. 13 is a perspective view illustrating astate of a second board unit of a flexible circuit board of FIG. 12 thatis bent.

Referring to FIGS. 8 to 13 , a voice coil motor (hereinafter referred toas VCM, 900) may include a rotor (100), a stator (200), a tilt unit(300), a rigid circuit board (700) and a flexible circuit board (800).In addition, the VCM (900) may further include a cover can (400),elastic members (500) and a base unit (600).

The rotor (100) is mounted with a lens (105), and serves to perform anauto focusing function by vertically moving relative to an upper surfaceof the base unit (600) arranged at a rear side with an image sensor.Furthermore, the rotor (100) performs a handshake correction function byhorizontally tiling relative to the upper surface (or horizontal plane)of the base unit (600) in response to the tilt unit (300, describedlater). The rotor (100) includes a bobbin (110) and a driving coil(120). In addition, the rotor (100) may further include a lens barrel(130) and a lens (105).

The bobbin (110) takes a cylindrical shape opened at an upper surfaceand a bottom surface. The bobbin (110) is formed at an inner surfacewith a female screw thread for fixing the lens barrel (130). The lensbarrel (130) is coupled by the lens (105). FIG. 9 illustrates the lensbarrel (130) not coupled to the lens (105). The bobbin (110) may beformed by injection molding process in the exemplary embodiment of thepresent disclosure.

The driving coil (120) is formed by winding an insulated long wire in acylindrical shape, and is arranged at an outer surface of the bobbin(110). The driving coil (120) may be directly wound on the outer surfaceof the bobbin (110), or may be attached to the outer surface of thebobbin (110) using an adhesive.

Referring to FIG. 8 , the bobbin (110) is arranged at a bottom surfacewith a first elastic member (520) which is one of the elastic member(500), and the first elastic member (520) is overlappingly arranged withfirst and second driving elastic members (510, 515).

The first driving elastic member (510) is coupled to the bottom surfaceof the bobbin (110) in an insulated state, and electrically connected toeach of both distal ends of the driving coil (120).

The first and second driving elastic members (510, 515) are respectivelyfixed to a square-shaped base (610) which is one of constituent elementsof the base unit (600, described later), and to a bottom spacer (630,described later). The second driving elastic members (515) iselastically coupled to a bottom surface of a housing (320, describedlater) to provide elasticity to the housing to return to an originalposition after the housing (320) is tilted.

Each of the second driving elastic members (515) is electricallyconnected to a tilt coil driving unit (336) of a tilt coil unit (330,described later). A driving signal applied to the tilt coil driving unit(336) is applied to the driving coil (120) through the second drivingelastic members (515).

The base (610) is fixed at a bottom surface thereof by a holder (620)having an opening (622) opposite to the lens (105) coupled to the bobbin(110), where the holder (620) is arranged at an inner surface with an IR(Infrared) filter (624) covering the opening (622) as shown in FIG. 9 .The holder (620) is arranged at an inner surface with an image sensor(625) opposite to the IR filter (624), where the image sensor (625) ismounted at a rigid circuit board (700) and electrically connected to therigid circuit board (700).

A technical term of ‘rigid circuit board (700)’ to be frequently used inthe present disclosure may be defined as a circuit board that is notflexible and difficult to be bent. The rigid circuit board (700) isshaped of a flat plate formed with a thin thickness, and is formed witha size adequate enough to be fixed into an inner surface of the holder(620).

The rigid circuit board (700) coupled to the holder (620) is tiltedalong with the base (610) and the holder (620), because the holder (620)is coupled to the base (610), whereby the image sensor (625)electrically connected to the rigid circuit board (700) is also tiltedalong with the rigid circuit board (700).

A flexible circuit board (800) is brought into contact with a bottomsurface of the rigid circuit board (700) and is electrically connectedto the rigid circuit board (700) to thereby provide an adequatestructure, where a driving signal is provided to the rigid circuit board(700) and the rigid circuit board (700) is tilted along with the holder(620).

The flexible circuit board (800) includes a first board unit (810), asecond board unit (820) and a third board unit (830). The first, secondand third board units (810, 820, 830) may be integrally formed in theexemplary embodiment of the present disclosure.

The flexible first board unit (810) is formed with a shape and sizesimilar to those of the rigid circuit board (700), and supports therigid circuit board (700). In a non-limiting example, an upper surfaceof the first board unit (810) and the rigid circuit board (700) may beattached together using an adhesive. Meanwhile, the bottom surface ofthe holder (620) is coated with an adhesive, and attached to the firstboard unit (810).

The second board unit (820) is formed at an edge of the first board unit(810), and provides a structure to allow the first board unit (810) totilt relative to the second board unit (820).

The second board unit (820) is symmetrically formed in a pair relativeto the first board unit (810) to allow the first board unit (810) totilt. The pair of second board units (820) takes a shape of a band, forexample, and each distal end of both sides of the second board units(820) is connected to both edges facing the first board unit (810). Eachof the pair of second board units (820) wraps three (3) edges adjacentto the first board unit (810), and each of the second board units (820)is symmetrically formed relative to a center of the first board unit(810).

Each of the second board units (820) symmetrically formed relative tothe first board unit (810) is formed with a through hole (822), whereeach of the through holes (822) is fixed by lugs (635) protruded fromthe bottom spacer (630). The first board unit (810) is tilted from thesecond board unit (820) due to fixture of the second board units (820)to the bottom spacer (630).

Each of the pair of second board units (820) is formed with signal lines(824, 826) electrically connected to the rigid circuit board (700),where the signal lines (824, 826) formed on the second board units (820)are extended to the third board units (830, described later) and thesignal lines (824, 826) are electrically connected to an outside circuitboard through the third board units (830). The third circuit board unit(830) includes first connection board units (832) and second connectionboard units (834).

The first connection board units (832) are integrally formed with a pairof second board units (820) and are protruded to an outside of the firstboard unit (810). The second connection board units are integrallyformed with a pair of first connection board units (832) and areelectrically connected to an outside circuit board.

The signal lines (824, 826) formed on each of the second board units(820) are electrically connected to the outside circuit board throughthe first connection board unit (832) and the second connection boardunit (834).

In the exemplary embodiment of the present disclosure, each width of thesecond board unit (820) can be reduced, because the signal lines (824,826) are dispersively arranged on the pair of second board units (820),whereby an area of the VCM (900) can be made in a more compact size.

Meanwhile, in a case the signal lines (824, 826) are dispersivelyarranged on the pair of second board units (820) in order to reduce thewidth of the second board unit (820), the first connection board unit(832) may rather further increase the area of the VCM (900), because thefirst connection board unit (832) is protruded to the outside from thesecond board units (820).

Thus, the first connection board unit (832) of the third board unit(830) is bent to be fixed to a lateral surface of the VCM (900) in theexemplary embodiment of the present disclosure, whereby the area of theVCM (900) is inhibited from increasing by the third board unit (830).

The base (610) and the holder (620) are accommodated inside asquare-framed bottom spacer (630), and the through hole of the secondboard unit (820) of the flexible circuit board (800) is press-fitted bya lug (635) protruded from a bottom end of the bottom spacer (630). Thebottom spacer (630) is coupled to a bottom cover can (420) by way of ahook coupling method.

The stator (200) includes a yoke (210) and a driving magnet (220). Theyoke (210) is arranged opposite to the driving coil (120) of the rotor(100), and includes an upper plate (212) and a lateral plate (214). Theupper plate (212) of the yoke (210) takes a shape of a square plateformed with an opening through which light having passed the lens (105)passes, and the lateral plate (214), four (4) in total, is extendeddownwards from an edge of the upper plate (212).

The driving magnet (220), four (4) in total, for example, is fixed to aninner surface of the lateral plate (214), and arranged opposite to thedriving coil (120).

The rotor (100) is moved to a direction facing an upper surface of thebase (610) by forces generated by a magnetic field from the drivingmagnet (220) and a magnetic field from the driving coil (120). A gapbetween the image sensor (625) arranged at a rear surface of the base(610) and the lens (105) can be adjusted by the rotor (100) moving tothe direction facing an upper surface of the base (610).

The tilt unit (300) includes a tilt magnet (310), a housing (320), atilt coil unit (330) and a spacer (340). The tilt magnet (310) isarranged at an outer surface of the lateral plate (214) of the yoke(210). Each of the tilt magnets (310), four (4) in total, is arranged oneach of the four (4) lateral plates (214) of the yoke (210). In theexemplary embodiment of the present disclosure, each of the tilt magnets(310) may include a 2-pole magnetizing flat magnet, or a 4-polemagnetizing flat magnet, for example.

Although the tilt magnets (310) may be directly arranged on the lateralplate (214) of the yoke (210), the tilt magnet (310) is fixed to thelateral plate (214) of the yoke (210) using the housing (320) in theexemplary embodiment of the present disclosure.

The housing (320) is formed in a cylindrical shape opened at an uppersurface and a bottom surface, and is also formed in a shape of beingcoupled to an outer surface of the lateral plate (214) of the yoke(210). Four lateral plates (321) of the housing (320) are formed withopenings (322) for fixing each of the tilt magnets (310), where the tiltmagnet (310) is arranged on the yoke (210) using each of the openings(322).

Referring to FIG. 8 , the tilt coil unit (330) includes a tilt coil(332), a tilt coil housing (334) and a tilt coil driving unit (336).

The tilt coil (332) is formed by winding an insulated coil in arectangular shape to allow a slit-shaped opening to be centrally formed,and is arranged opposite to the four (4) tilt magnets (310) each coupledto each of four (4) lateral plates (321) of the housing (320).

Because the tilt coil (332) must be arranged opposite to the four (4)tilt magnets (310), four (4) tilt coils (332) must be formed in the samenumber as that of the tilt magnets (310). A gap is formed between asurface of the tilt coil (332) and the tilt magnet (310) to allow therotor (100) to horizontally tilt. Both distal ends (332 a, 332 b) of theinsulated coil forming the tilt coil (332) are protruded to an uppersurface of the tilt coil (332).

In the exemplary embodiment of the present disclosure, the tilt coil(332) and the tilt magnet (310) are arranged to face each other, and anempty space is formed between the tilt coil (332) and the tilt magnet(310) to further enhance the forces generated by magnetic field from thetilt coil (332) and the magnetic field from the tilt magnet (310).

The tilt coil housing (334) serves to fix each of the tilt coils (332)arranged opposite to the four (4) tilt magnets (310). The tilt coilhousing (334) is opened at an upper surface and a bottom surface, andincludes four (4) lateral surfaces (335), and each of the lateralsurfaces (335) of the tilt coil housing (334) are formed with openingsfor fixing each of the tilt coils (332).

The tilt coil driving unit (336) functions to apply a tilt drivingsignal to each of the tilt coils (332), may include a flexible circuitboard, and covers each of the tilt coils (332) to be electricallyconnected to each of the tilt coils (332). The tilt coil driving unit(336) includes a first tilt coil driving unit (337), a second tilt coildriving unit (338) and a third tilt coil driving unit (339).

The first, second and third tilt coil driving units (337, 338, 339) areintegrally formed in the exemplary embodiment of the present disclosure,and each of the first, second and third tilt coil driving units (337,338, 339) includes a flexible circuit board.

The first tilt coil driving unit (337) is arranged at an upper surfaceof the tilt coil housing (334), and takes a shape of a square bandformed therein with an opening. The second tilt coil driving unit (338)is extended from an outer surface of the first tilt coil driving unit(337) formed in the shape of a square band. Each of the second tilt coildriving units (338) takes a shape of a square plate covering a rearsurface of the four (4) tilt coils (332).

In the exemplary embodiment of the present disclosure, the second tiltcoil driving units (338) are coupled to a rear surface of the tilt coil(332) opposite to the tilt magnets (310). The second tilt coil drivingunits (338) and the tilt coil (332) may be mutually attached by using anadhesive, for example.

Because the second tilt coil driving units (338) are coupled to a rearsurface of the tilt coil (332) using an adhesive in the exemplaryembodiment of the present disclosure, an empty space is formed betweenthe tilt coil (332) and the tilt magnets (310), whereby a tiltperformance of the rotor (100) can be further enhanced by the magneticfield generated by the tilt coil (332) and the tilt magnet (310).

A part of the second tilt coil driving units (338) is electricallyconnected to a part of the driving coil (120) electrically connected tothe first elastic member (520).

Meanwhile, connection openings (337 a) are formed between the first andsecond tilt coil driving units (337, 338), where the connection openings(337 a) are formed at a position corresponding to that of both distalends (332 a, 332 b) of the tilt coil (332). The both distal ends (332 a,332 b) of the tilt coil (332) are inserted into the connection openings(337 a), and may be electrically connected to a terminal formed at thefirst tilt coil driving unit (337) using a welding or a conductiveadhesive tape. Furthermore, the terminal formed at the first tilt coildriving unit (337) and the both distal ends (332 a, 332 b) of the tiltcoil (332) can be easily assembled by electrical connection fromoutside.

The third tilt coil driving unit (339) is extended from any one of thefour (4) second tilt coil driving units (338), and electricallyconnected to an outside circuit board, and a tilt driving signal appliedfrom the outside circuit board is applied to each of the tilt coils(332) through the third tilt coil driving unit (339), the second tiltcoil driving unit (338) and the first tilt coil driving unit (337).

The third tilt coil driving unit (339) in the exemplary embodiment ofthe present disclosure is formed in parallel with the third board unit(830) of the circuit board (800).

Meanwhile, a part of the second elastic member (530) which is one of theelastic member (500) is arranged on the upper surface of the housing(320) fixing the tilt magnet (310) and on the upper surface (212) of theyoke (210), and a part of the second elastic member (530) is fixed bythe bobbin (110). That is, the bobbin (110) is elastically coupled bythe first elastic member (520) coupled to the bottom end of the bobbin(110) and the second elastic member (530) coupled to the upper surfaceof the bobbin (110).

The cover can (400) inhibits the rotor (100), the stator (200), the tiltunit (300) and the elastic member (500) from being destructed by outsidevibration and shock. The cover can (400) includes an upper cover can(410) and a bottom cover can (420). The upper cover can (410) includesan upper plate (412) and a lateral plate (414). The upper plate (412) ofthe cover can (400) takes a shape of a square plate having an openingexposing the lens (105), and the lateral plate (414) is extended fromthe upper plate (412).

In the exemplary embodiment of the present disclosure, the rotor (100)is horizontally tilted by a magnetic field generated from the tiltmagnet (310) and a magnetic field from the tilt coil (332) to perform ahandshake correction function, and the rotor (100) is vertically movedby the magnetic field from the driving magnet (220) and the magneticfield from the driving coil (120) to perform an auto focusing function.

Meanwhile, in order for the rotor (100) to perform the handshakecorrection function by horizontal tilt and to perform the auto focusingfunction by vertical movement, a space must be formed between an innersurface of the upper plate (412) of the upper cover can (410) and therotor (100). However, in a case a large space is formed between theinner surface of the upper plate (412) of the upper cover can (410) andthe rotor (100) to perform the handshake correction function or the autofocusing function, it is inevitable that an entire volume and a heightof the VCM (900) are greatly increased.

In order to realize a tilt space for performing the handshake correctionfunction or the auto focusing function without increasing the entirevolume and the height of the VCM (700) in the exemplary embodiment ofthe present disclosure, an upper surface (323) of the housing (320)opposite to the inner surface of the upper plate (412) of the uppercover can (410) of the cover can (400) is placed at a position lowerthan an upper end of the bobbin (110) of the rotor (100). The uppersurface (323) of the housing (320) is arranged at a position lower thanthe upper end of the bobbin (110). Preferably, the upper surface (323)of the housing (320) may be arranged on a same planar surface as that ofthe upper surface (212) of the yoke (210).

In a case the upper surface (323) of the housing (320) is placed at aposition lower than the upper end of the bobbin (110), or on a sameplanar surface as that of the upper surface (212) of the yoke (210), aspace is formed where the upper surface (323) of the housing (320)coupled to the rotor (100) performing a handshake correction function bybeing horizontally tilted relative to the horizontal surface or to therotor (100) vertically moving relative to the horizontal surface is notinterfered with an inner surface of the upper plate (412) of the uppercover can (410) or the tilt coil driving unit (336).

Furthermore, in a case the upper surface (323) of the housing (320) isplaced at a position lower than the upper end of the bobbin (110), or ona same planar surface as that of the upper surface (212) of the yoke(210), the entire volume and the height of the VCM (900) are notincreased.

In order to inhibit the upper cover can (410) of the housing (320) frombeing interfered with the upper surface (212) of the housing (210), athickness of the lateral plate (321) of the housing (210) is formed lessthan the thickness of the tilt magnet (310), whereby a part of the uppersurface (212) of the housing (210) is exposed from the tilt magnet(310).

Meanwhile, the upper surface (323) of the housing (320) is arranged withthe second elastic member (530), and the second elastic member (530) isfixed by the spacer (340), and in order for the spacer (340) to inhibitthe rotor (100) from being interfered with the cover can (410) of thecover can (400) or with the tilt coil driving unit (336), an uppersurface (341) of the spacer (340) is arranged at a position lower thanthe upper end of the bobbin (110), and a lateral surface of the spacer(340) is preferably so formed as not to protrude from an outer surfaceof the lateral plate (321) of the housing (210).

As mentioned in detail in the above description, the VCM according tothe present disclosure has an advantageous effect in that the VCM iselectrically connected to a rigid circuit board mounted with an imagesensor, and signal lines of a flexible circuit board capable of tiltingthe rigid circuit board is dispersively arranged to reduce an area ofthe flexible circuit board and to reduce an entire volume of the VCM.

Fourth Exemplary Embodiment

FIG. 14 is an exploded perspective view illustrating a VCM according toa fourth exemplary embodiment of the present disclosure, FIG. 15 is anassembled cross-sectional view of FIG. 14 , FIG. 16 is an extractedperspective view illustrating a housing and a tilt magnet of FIG. 14 ,FIG. 17 is a perspective view illustrating a flexible circuit board ofFIG. 15 , and FIG. 18 is a cross-sectional view taken along line I-I′ ofFIG. 17 .

Referring to FIGS. 14 to 18 , a voice coil motor (hereinafter referredto as VCM, 900) may include a rotor (100), a stator (200), a tilt unit(300), a rigid circuit board (700) and a flexible circuit board (800).In addition, the VCM (900) may further include a cover can (400),elastic members (500) and a base unit (600).

The rotor (100) is mounted with a lens (105), and serves to perform anauto focusing function by vertically moving relative to an upper surfaceof the base unit (600) arranged at a rear side with an image sensor.Furthermore, the rotor (100) performs a handshake correction function byhorizontally tiling relative to the upper surface (or horizontal plane)of the base unit (600) in response to the tilt unit (300, describedlater). The rotor (100) includes a bobbin (110) and a driving coil(120). In addition, the rotor (100) may further include a lens barrel(130) and a lens (105).

The bobbin (110) takes a cylindrical shape opened at an upper surfaceand a bottom surface. The lens barrel (130) is coupled by the lens(105). FIG. 2 illustrates the lens barrel (130) not coupled to the lens(105). The bobbin (110) may be formed by injection molding process inthe exemplary embodiment of the present disclosure.

The driving coil (120) is formed by winding an insulated long wire in acylindrical shape, and is arranged at an outer surface of the bobbin(110). The driving coil (120) may be directly wound on the outer surfaceof the bobbin (110), or may be attached to the outer surface of thebobbin (110) using an adhesive.

Referring to FIG. 14 , the bobbin (110) is arranged at a bottom surfacewith a first elastic member (520) which is one of the elastic member(500), and the first elastic member (520) is overlappingly arranged withfirst and second driving elastic members (510, 515).

The first driving elastic member (510) is coupled to the bottom surfaceof the bobbin (110) in an insulated state, and electrically connected toeach of both distal ends of the driving coil (120).

The first and second driving elastic members (510, 515) are respectivelyfixed to a square-shaped base (610), which is one of constituentelements of the base unit (600, described later), and to a bottom spacer(630, described later). The second driving elastic members (515) iselastically coupled to a bottom surface of a housing (320, describedlater) to provide elasticity to the housing to return to an originalposition after the housing (320) is tilted.

Each of the second driving elastic members (515) is electricallyconnected to a flexible circuit board (800, described later). A drivingsignal applied to the flexible circuit board (800) is applied to thedriving coil (120) through the first and second driving elastic members(510, 515).

The base (610) is fixed at a bottom surface thereof by a holder (620)having an opening (622) opposite to the lens (105) coupled to the bobbin(110), where the holder (620) is arranged at an inner surface with an IR(Infrared) filter (624) covering the opening (622) as shown in FIG. 2 .

Referring to FIGS. 14, 17 and 18 , the holder (620) is arranged at aninner surface with an image sensor (625) opposite to the IR filter(624), where the image sensor (625) is mounted at a rigid circuit board(700, described later) and electrically connected to the rigid circuitboard (700).

A technical term of ‘rigid circuit board (700)’ to be frequently used inthe present disclosure may be defined as a circuit board that is notflexible and difficult to be bent.

A flexible circuit board (800) in the exemplary embodiment of thepresent disclosure is arranged on an upper surface of the rigid circuitboard (700).

The flexible circuit board (800) is brought into contact with an uppersurface of the rigid circuit board (700) and is electrically connectedto the rigid circuit board (700) to thereby provide an adequatestructure, where a driving signal is provided to the rigid circuit board(700) and the rigid circuit board (700) is tilted along with the holder(620).

The flexible circuit board (800) includes a first board unit (810), asecond board unit (820) and a third board unit (830). The first, secondand third board units (810, 820, 830) may be integrally formed in theexemplary embodiment of the present disclosure.

The flexible circuit board (800) includes an opening (815) exposing theimage sensor (625), and a portion where the image sensor (625) of thefirst board unit (810) is exposed and the rigid circuit board (700) iscovered is attached to the rigid circuit board (700) using an adhesive.

The image sensor (625) cannot be directly and electrically coupled tothe rigid circuit board (700) because an upper surface of the rigidcircuit board (700) is covered by the first board unit (810) of theflexible circuit board (800). Thus, an upper surface of the image sensor(625) is arranged with first terminals (627), and an upper surface ofthe first board unit (810) is arranged with second terminals (818)corresponding to the first terminals (627), where the first and secondterminals (627, 818) are wire-bonded by a conductive wire (628).

In a case the opening (815) is formed on the first board unit (810) ofthe flexible circuit board (800), and the image sensor (625) is insertedinto the opening (815) through an opening of the first board unit (810),the image sensor (625) and the flexible circuit board (800) areoverlapped to reduce the volume and height of the VCM (900) as much asthe thickness of the flexible circuit board (800), and a spatialutilization of a rear surface of the flexible circuit board (800) can begreatly enhanced to further reduce the volume and height of the VCM(900).

Meanwhile, a bottom surface of the holder (620) is coated with anadhesive to allow the holder (620) to be attached to the first boardunit (810) of the flexible circuit board (800), and the first board unit(810) is arranged on an upper surface of the rigid circuit board (700),whereby a bottom shape of the holder (620) can be simplified and anadhered area between the holder (620) and the first board unit (810) canbe improved as well.

The second board unit (820) is formed at an edge of the first board unit(810), and provides a tilt structure to allow the first board unit (810)to tilt relative to the second board unit (820).

The second board unit (820) is symmetrically formed in a pair relativeto the first board unit (810) to allow the first board unit (810) totilt. The pair of second board units (820) takes a shape of a band, forexample, and each distal end of both sides of the second board units(820) is connected to both edges facing the first board unit (810). Eachof the pair of second board units (820) wraps three (3) edges adjacentto the first board unit (810), and each of the second board units (820)is symmetrically formed relative to a center of the first board unit(810).

Each of the second board units (820) symmetrically formed relative tothe first board unit (810) is formed with a through hole (822), whereeach of the through holes (822) is fixed by lugs (635) protruded fromthe bottom spacer (630) illustrated in FIG. 2 . The first board unit(810) is tilted from the second board unit (820) due to fixture of thesecond board units (820) to the bottom spacer (630).

Each of the pair of second board units (820) is formed with signal lines(824, 826) electrically connected to the rigid circuit board (700),where the signal lines (824, 826) formed each of on the second boardunits (820) are extended to the third board units (830, described later)and the signal lines (824, 826) are electrically connected to an outsidecircuit board through the third board units (830). The third circuitboard unit (830) includes first connection board units (832) and secondconnection board units (834).

The first connection board units (832) are integrally formed with a pairof second board units (820) and are protruded to an outside of the firstboard unit (810). The second connection board units are integrallyformed with a pair of first connection board units (832) and areelectrically connected to an outside circuit board.

The signal lines (824, 826) formed on each of the second board units(820) are electrically connected to the outside circuit board throughthe first connection board unit (832) and the second connection boardunit (834).

In the exemplary embodiment of the present disclosure, each width of thesecond board unit (820) can be reduced, because the signal lines (824,826) are dispersively arranged on the pair of second board units (820),whereby an area of the VCM (900) can be made in a more compact size.

Meanwhile, in a case the signal lines (824, 826) are dispersivelyarranged on the pair of second board units (820) in order to reduce thewidth of the second board unit (820), the first connection board unit(832) may rather further increase the area of the VCM (900), because thefirst connection board unit (832) is protruded to the outside from thesecond board units (820).

Thus, the first connection board unit (832) of the third board unit(830) is bent to be fixed to a lateral surface of the VCM (900) in theexemplary embodiment of the present disclosure, whereby the area of theVCM (900) is inhibited from increasing by the third board unit (830).

The base (610) and the holder (620) are accommodated inside asquare-framed bottom spacer (630), and the through hole of the secondboard unit (820) of the flexible circuit board (800) is press-fitted bya lug (632) protruded from a bottom end of the bottom spacer (630). Thebottom spacer (630) is coupled to a bottom cover can (420) by way of ahook coupling method.

The stator (200) includes a yoke (210) and a driving magnet (220). Theyoke (210) is arranged opposite to the driving coil (120) of the rotor(100), and includes an upper plate (212) and a lateral plate (214). Theupper plate (212) of the yoke (210) takes a shape of a square plateformed with an opening through which light having passed the lens (105)passes, and the lateral plate (214), four (4) in total, is extendeddownwards from an edge of the upper plate (212).

The driving magnet (220), four (4) in total, for example, is fixed to aninner surface of the lateral plate (214), and arranged opposite to thedriving coil (120).

The rotor (100) is moved to a direction facing an upper surface of thebase (610) by forces generated by a magnetic field from the drivingmagnet (220) and a magnetic field from the driving coil (120). A gapbetween the image sensor (625) arranged at a rear surface of the base(610) and the lens (105) can be adjusted by the rotor (100) moving tothe direction facing an upper surface of the base (610).

The tilt unit (300) includes a tilt magnet (310), a housing (320), atilt coil unit (330) and a spacer (340). The tilt magnet (310) isarranged at an outer surface of the lateral plate (214) of the yoke(210). Each of the tilt magnets (310), four (4) in total, is arranged oneach of the four (4) lateral plates (214) of the yoke (210). In theexemplary embodiment of the present disclosure, each of the tilt magnets(310) may include a 2-pole magnetizing flat magnet, or a 4-polemagnetizing flat magnet, for example.

Referring to FIGS. 14 and 16 , it may be acceptable to allow the tiltmagnets (310) to be directly arranged on the lateral plate (214) of theyoke (210), the tilt magnet (310) is fixed to the lateral plate (214) ofthe yoke (210) using the housing (320) in the exemplary embodiment ofthe present disclosure.

The housing (320) is formed in a cylindrical shape opened at an uppersurface and a bottom surface, and is also formed in a shape of beingcoupled to an outer surface of the lateral plate (214) of the yoke(210). Four lateral plates (321) of the housing (320) are formed withopenings (322) for fixing each of the tilt magnets (310), where the tiltmagnet (310) is arranged on the yoke (210) using each of the openings(322).

The tilt coil unit (330) includes a tilt coil (332), a tilt coil housing(334) and a tilt coil driving unit (336).

The tilt coil (332) is formed by winding an insulated coil in arectangular shape to allow a slit-shaped opening to be centrally formed,and is arranged opposite to the four (4) tilt magnets (310) each coupledto each of four (4) lateral plates (321) of the housing (320).

A gap is formed between a surface of the tilt coil (332) and the tiltmagnet (310) to allow the rotor (100) to horizontally tilt.

The tilt coil housing (334) serves to fix each of the tilt coils (332)arranged opposite to the four (4) tilt magnets (310). The tilt coilhousing (334) is opened at an upper surface and a bottom surface, andincludes four (4) lateral surfaces (335), and each of the lateralsurfaces (335) of the tilt coil housing (334) are formed with openingsfor fixing each of the tilt coils (332).

The tilt coil driving unit (336) functions to apply a tilt drivingsignal to each of the tilt coils (332), may include a flexible circuitboard, and covers each of the tilt coils (332) to be electricallyconnected to each of the tilt coils (332). The tilt coil driving unit(336) includes a first tilt coil driving unit (337), a second tilt coildriving unit (338) and a third tilt coil driving unit (339). An opening(337 a) is formed between the first and second tilt coil driving units(337, 338).

Meanwhile, a part of the second elastic member (530) which is one of theelastic member (500) is arranged on the upper surface of the housing(320) fixing the tilt magnet (310) and on the upper surface (212) of theyoke (210), and a part of the second elastic member (530) is fixed bythe bobbin (110). That is, the bobbin (110) is elastically coupled bythe first elastic member (520) coupled to the bottom end of the bobbin(110) and the second elastic member (530) coupled to the upper surfaceof the bobbin (110).

The cover can (400) inhibits the rotor (100), the stator (200), the tiltunit (300) and the elastic member (500) from being destructed by outsidevibration and shock. The cover can (400) includes an upper cover can(410) and a bottom cover can (420). The upper cover can (410) includesan upper plate (412) and a lateral plate (414). The upper plate (412) ofthe cover can (400) takes a shape of a square plate having an openingexposing the lens (105), and the lateral plate (414) is extended fromthe upper plate (412).

In the exemplary embodiment of the present disclosure, the rotor (100)is horizontally tilted by a magnetic field generated from the tiltmagnet (310) and a magnetic field from the tilt coil (332) to perform ahandshake correction function, and the rotor (100) is vertically movedby the magnetic field from the driving magnet (220) and the magneticfield from the driving coil (120) to perform an auto focusing function.

Meanwhile, in order for the rotor (100) to perform the handshakecorrection function by horizontal tilt and to perform the auto focusingfunction by vertical movement, a space must be formed between an innersurface of the upper plate (412) of the upper cover can (410) and therotor (100). However, in a case a large space is formed between theinner surface of the upper plate (412) of the upper cover can (410) andthe rotor (100) to perform the handshake correction function or the autofocusing function, it is inevitable that an entire volume and a heightof the VCM (900) are greatly increased.

In order to realize a tilt space for performing the handshake correctionfunction or the auto focusing function without increasing the entirevolume and the height of the VCM (700) in the exemplary embodiment ofthe present disclosure, an upper surface (323) of the housing (320)opposite to the inner surface of the upper plate (412) of the uppercover can (410) of the cover can (400) is placed at a position lowerthan an upper end of the bobbin (110) of the rotor (100). The uppersurface (323) of the housing (320) is arranged at a position lower thanthe upper end of the bobbin (110). Preferably, the upper surface (323)of the housing (320) may be arranged on a same planar surface as that ofthe upper surface (212) of the yoke (210).

In a case the upper surface (323) of the housing (320) is placed at aposition lower than the upper end of the bobbin (110), or on a sameplanar surface as that of the upper surface (212) of the yoke (210), aspace is formed where the upper surface (323) of the housing (320)coupled to the rotor (100) performing a handshake correction function bybeing horizontally tilted relative to the horizontal surface or to therotor (100) vertically moving relative to the horizontal surface is notinterfered with an inner surface of the upper plate (412) of the uppercover can (410) or the tilt coil driving unit (336).

Furthermore, in a case the upper surface (323) of the housing (320) isplaced at a position lower than the upper end of the bobbin (110), or ona same planar surface as that of the upper surface (212) of the yoke(210), the entire volume and the height of the VCM (900) are notincreased.

In order to inhibit the upper cover can (410) of the housing (320) frombeing interfered with the upper surface (212) of the housing (210), athickness of the lateral plate (321) of the housing (210) is formed lessthan the thickness of the tilt magnet (310), whereby a part of the uppersurface (212) of the housing (210) is exposed from the tilt magnet(310).

Meanwhile, the upper surface (323) of the housing (320) is arranged withthe second elastic member (530), and the second elastic member (530) isfixed by the spacer (340), and in order for the spacer (340) to inhibitthe rotor (100) from being interfered with the cover can (410) of thecover can (400) or with the tilt coil driving unit (336), an uppersurface (341) of the spacer (340) is arranged at a position lower thanthe upper end of the bobbin (110), and a lateral surface of the spacer(340) is preferably so formed as not to protrude from an outer surfaceof the lateral plate (321) of the housing (210).

As mentioned in detail in the above description, the VCM according tothe present disclosure has an advantageous effect in that signal linesof a flexible circuit board for tilting an image sensor along with arotor are dispersively arranged to reduce an area of the flexiblecircuit board, and the flexible circuit board is inserted into the imagesensor arranged on an upper surface of a rigid circuit board to reducean entire volume of the VCM.

The above-mentioned VCM according to the present disclosure may,however, be embodied in many different forms and should not be construedas limited to the embodiment set forth herein. Thus, it is intended thatembodiment of the present disclosure may cover the modifications andvariations of this disclosure provided they come within the scope of theappended claims and their equivalents. While particular features oraspects may have been disclosed with respect to several embodiments,such features or aspects may be selectively combined with one or moreother features and/or aspects of other embodiments as may be desired.

What is claimed is:
 1. A camera module comprising: a first circuitboard; an image sensor disposed on the circuit board; a lens disposed onthe image sensor; a first magnet and a first coil configured to move thelens with respect to the image sensor in an optical axis direction; asecond magnet and a second coil configured to tilt both the lens and theimage sensor; and a second circuit board electrically connected with thefirst circuit board, wherein the second circuit board comprises aflexible circuit board.
 2. The camera module of claim 1, wherein thefirst circuit board comprises a rigid circuit board.
 3. The cameramodule of claim 1, wherein a shape of the flexible circuit board ischangeable to movably support the first circuit board.
 4. The cameramodule of claim 1, wherein the first coil is overlapped with the secondcoil in a direction perpendicular to the optical axis direction.
 5. Thecamera module of claim 1, wherein the first coil is overlapped with thesecond magnet in a direction perpendicular to the optical axisdirection.
 6. The camera module of claim 1, wherein the second coilcomprises a first coil part and a second coil part, wherein the firstcircuit board is configured to move in a first direction when a currentis applied to the first coil part, and wherein the second circuit boardis configured to move in a second direction different form the firstdirection when a current is applied to the second coil part.
 7. Thecamera module of claim 1, wherein the flexible circuit board comprises abent shape.
 8. The camera module of claim 1, wherein the second circuitboard comprises a first part connected with the first circuit board, asecond part disposed outside the first part, and a connection partconnecting the first part and the second part.
 9. The camera module ofclaim 8, wherein the connection part of the second circuit boardelastically connects the first part and the second part.
 10. The cameramodule of claim 1, wherein the image sensor is electrically connectedwith the second circuit board.
 11. The camera module of claim 1, whereinthe first coil is electrically connected with the second circuit board.12. The camera module of claim 1, comprising: a first housing; a secondhousing disposed in the first housing; and a bobbin disposed in thesecond housing and coupled with the lens.
 13. The camera module of claim12, wherein the first coil is disposed on the bobbin, and wherein thefirst magnet is disposed on the second housing.
 14. The camera module ofclaim 12, wherein the second coil is disposed on the first housing, andwherein the second magnet is disposed on the second housing.
 15. Amobile phone comprising the camera module of claim
 1. 16. A cameramodule comprising: a first circuit board; an image sensor disposed onthe circuit board; a lens disposed on the image sensor; a first magnetand a first coil configured to move the lens with respect to the imagesensor in an optical axis direction; a second magnet and a second coilconfigured to tilt the image sensor; and a second circuit boardelectrically connected with the first circuit board, wherein the secondcircuit board comprises a bent shape.
 17. The camera module of claim 16,wherein the first coil is electrically connected with the second circuitboard.
 18. The camera module of claim 17, comprising first and seconddriving elastic members electrically connecting the second circuit boardand the first coil.
 19. The camera module of claim 16, wherein the bentshape of the second circuit board is changeable to movably support thefirst circuit board.
 20. A camera module comprising: a first circuitboard; an image sensor disposed on the circuit board; a lens disposed onthe image sensor; and a first magnet and a first coil configured to movethe lens with respect to the image sensor in an optical axis direction.